# Copyright 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

from recipe_engine import recipe_api
from recipe_engine import util as recipe_util

from .util import GTestResults, TestResults

# TODO(luqui): Destroy this DEPS hack.
import DEPS
JsonOutputPlaceholder = DEPS['json'].api.JsonOutputPlaceholder

class TestResultsOutputPlaceholder(JsonOutputPlaceholder):
  def result(self, presentation, test):
    ret = super(TestResultsOutputPlaceholder, self).result(presentation, test)
    return TestResults(ret)


class GTestResultsOutputPlaceholder(JsonOutputPlaceholder):
  def result(self, presentation, test):
    ret = super(GTestResultsOutputPlaceholder, self).result(presentation, test)
    return GTestResults(ret)

class TestUtilsApi(recipe_api.RecipeApi):

  # Some test runners (such as run_web_tests.py and python tests) returns the
  # number of failures as the return code. They need to cap the return code at
  # 101 to avoid overflow or colliding with reserved values from the shell.
  MAX_FAILURES_EXIT_STATUS = 101

  # This magic string is depended on by other infra tools.
  INVALID_RESULTS_MAGIC = 'TEST RESULTS WERE INVALID'

  @staticmethod
  def format_step_text(data):
    """
    Returns string suitable for use in a followup function's step result's
    presentation step text.

    Args:
      data - iterable of sections, where each section is one of:
        a) tuple/list with one element for a single-line section
           (always displayed)
        b) tuple/list with two elements where first one is the header,
           and the second one is an iterable of content lines; if there are
           no contents, the whole section is not displayed
    """
    step_text = []
    for section in data:
      if len(section) == 1:
        # Make it possible to display single-line sections.
        step_text.append('<br/>%s<br/>' % section[0])
      elif len(section) == 2:
        # Only displaying the section (even the header) when it's non-empty
        # simplifies caller code.
        if section[1]:
          step_text.append('<br/>%s<br/>' % section[0])
          step_text.extend(('%s<br/>' % line for line in section[1]))
      else:  # pragma: no cover
        raise ValueError(
            'Expected a one or two-element list, got %r instead.' % section)
    return ''.join(step_text)

  def run_tests(self, caller_api, tests, suffix):
    """
    Utility function for running a list of tests and returning the failed tests.

    Args:
      caller_api - caller's recipe API; this is needed because self.m here
                   is different than in the caller (different recipe modules
                   get injected depending on caller's DEPS vs. this module's
                   DEPS)
      tests - iterable of objects implementing the Test interface above
      suffix - custom suffix, e.g. "with patch", "without patch" indicating
               context of the test run
    Returns:
      The list of failed tests.
    """
    failed_tests = []

    with self.m.step.nest('test_pre_run'):
      for t in tests:
        try:
          t.pre_run(caller_api, suffix)
        except caller_api.step.InfraFailure:
          raise
        except caller_api.step.StepFailure:
          failed_tests.append(t)

    for t in tests:
      try:
        t.run(caller_api, suffix)
      except caller_api.step.InfraFailure:
        raise
      except caller_api.step.StepFailure:
        failed_tests.append(t)
        if t.abort_on_failure:
          raise

    return failed_tests

  def run_tests_with_patch(self, caller_api, tests):
    failing_tests = self.run_tests(caller_api, tests, 'with patch')
    failing_test_names = set(f.name for f in failing_tests)
    with self.m.step.defer_results():
      for t in tests:
        if not t.has_valid_results(caller_api, 'with patch'):
          self._invalid_test_results(t)
          failing_test_names.discard(t)
        elif t.failures(caller_api, 'with patch'):
          if t.name not in failing_test_names:
            failing_tests.append(t)
            failing_test_names.add(t.name)
    return failing_tests

  def determine_new_failures(self, caller_api, tests, deapply_patch_fn):
    """
    Utility function for running steps with a patch applied, and retrying
    failing steps without the patch. Failures from the run without the patch are
    ignored.

    Args:
      caller_api - caller's recipe API; this is needed because self.m here
                   is different than in the caller (different recipe modules
                   get injected depending on caller's DEPS vs. this module's
                   DEPS)
      tests - iterable of objects implementing the Test interface above
      deapply_patch_fn - function that takes a list of failing tests
                         and undoes any effect of the previously applied patch
    """
    # Convert iterable to list, since it is enumerated multiple times.
    tests = list(tests)

    failing_tests = self.run_tests_with_patch(caller_api, tests)
    if not failing_tests:
      return

    try:
      result = deapply_patch_fn(failing_tests)
      self.run_tests(caller_api, failing_tests, 'without patch')
      return result
    except Exception as e:
      # This except is here to try to debug a strange error. Builds like
      # https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac_chromium_rel_ng/80909
      # seem to be failing before they run any steps to de-apply the patch. The
      # hypothesis is that an exception is being thrown and ignored due to the
      # defer_results() call below.
      text = 'exception occured while de-applying patch\n%s' % (str(e))
      step = self.m.python.succeeding_step('deapply_failure', text)
      step.presentation.status = self.m.step.WARNING
      step.presentation.logs['exception'] = [
          str(e), '\n', self.m.traceback.format_exc()]
      raise
    finally:
      with self.m.step.defer_results():
        for t in failing_tests:
          self._summarize_retried_test(caller_api, t)

  def _invalid_test_results(self, test):
    self.m.tryserver.set_invalid_test_results_tryjob_result()
    self.m.python.failing_step(test.name, self.INVALID_RESULTS_MAGIC)

  def _summarize_retried_test(self, caller_api, test):
    """Summarizes test results and exits with a failing status if there were new
    failures."""
    if not test.has_valid_results(caller_api, 'without patch'):
      self._invalid_test_results(test)

    ignored_failures = set(test.failures(caller_api, 'without patch'))
    new_failures = (
      set(test.failures(caller_api, 'with patch')) - ignored_failures)

    self.m.tryserver.add_failure_reason({
      'test_name': test.name,
      'new_failures': sorted(new_failures),
    })

    step_name = '%s (retry summary)' % test.name
    step_text = self.format_step_text([
        ['failures:', new_failures],
        ['ignored:', ignored_failures]
    ])
    try:
      if new_failures:
        self.m.python.failing_step(step_name, step_text)
      else:
        self.m.python.succeeding_step(step_name, step_text)
    finally:
      if new_failures:
        self.m.tryserver.set_test_failure_tryjob_result()
      elif ignored_failures:
        self.m.step.active_result.presentation.status = self.m.step.WARNING

      # TODO(crbug/706192): Remove the check for webkit_tests, once this step
      # name no longer exists.
      if test.name in ('webkit_tests', 'webkit_layout_tests'):
        self._archive_retry_summary({
            'failures': sorted(new_failures),
            'ignored': sorted(ignored_failures)
        })

  def _archive_retry_summary(self, retry_summary):
    """Archives the retry summary as JSON, storing it alongside the results
    from the first run."""
    script = self.m.chromium.package_repo_resource(
        'scripts', 'slave', 'chromium', 'archive_layout_test_retry_summary.py')
    args = [
        '--retry-summary-json', self.m.json.input(retry_summary),
        '--build-number', self.m.properties['buildnumber'],
        '--builder-name', self.m.properties['buildername'],
        '--gs-bucket', 'gs://chromium-layout-test-archives',
    ]
    args += self.m.build.slave_utils_args
    self.m.build.python('archive_retry_summary', script, args)

  def create_results_from_json(self, data):
    return TestResults(data)

  def create_results_from_json_if_needed(self, data):
    if data is None:
      raise TypeError('Invalid data given')
    if isinstance(data, TestResults):
      return data
    return TestResults(data)

  @recipe_util.returns_placeholder
  def test_results(self, add_json_log=True):
    """A placeholder which will expand to '/tmp/file'.

    The recipe must provide the expected --json-test-results flag.

    The test_results will be an instance of the TestResults class.
    """
    return TestResultsOutputPlaceholder(self, add_json_log)

  @recipe_util.returns_placeholder
  def gtest_results(self, add_json_log=True):
    """A placeholder which will expand to
    '--test-launcher-summary-output=/tmp/file'.

    Provides the --test-launcher-summary-output flag since --flag=value
    (i.e. a single token in the command line) is the required format.

    The test_results will be an instance of the GTestResults class.
    """
    return GTestResultsOutputPlaceholder(self, add_json_log)